Pool cover



Nov. 19, 1963 H. J. NEWGARD 3,110,908

POOL COVER Filed Oct. 25. 1961 2 Sheets-Sheet l INVENTOR NEWGARD ATTORNEY Nov. 19, 1963 H. J. NEWGARD 3,110,908

- POOL COVER Filed Oct. 25, 1961 1 2 Sheets-Sheet 2 z// /4Q44z/// INVENTOR HENRI J NE W GARD ATTORNEY United States Patent 3,110,908 P061, EIQVER Henry ll. Newgard, 4366 Evergreen Drive, Adrian, Mich. Filed Oct. 25, 1961, Ser. No. 147,583 12 Claims. (Cl. i -r72 The invention pertains to cover apparatus for swimming pools and other objects desired to be covered or encased in protective sheet material, and particularly relates to cover apparatus primarily constructed of a synthetic, chemically inert plastic material.

With the very common usage of swimming pools, both public and private, the need for an attractive and elfective pool cover has been recognized. Such covers have several purposes in that they protect children, adults, and animals from falling into untended pools as well as improve the appearance of the pool, discourage unauthorized swimming, reduce pool maintenance by keeping debris out of the pool, reduce the disinfectant and heating costs and reduce the growth of algae. Pool covers are currently available on the market. However, such covers are of such construction as to be diificultto install, require stringers and tension devices to hold the cover in position necessitating the installation of complicated anchoring devices, and are usually very expensive.

It is an object of the invention to provide a very lightweight pool cover apparatus constructed of a high strength plastic material which is chemically inert and will not re quire maintenance nor be adversely affected by the elements so as to maintain an attractive appearance over the years.

It is a further object of the invention to provide pool cover apparatus which may be easily handled and assembled in position upon the pool and wherein the anchor means for the cover may be readily installed, is unobtrusive and permits easy attachment with the anchor ropes.

Yet a further object of the invention is to provide pool cover apparatus including a cover screen and anchor ropes wherein the screen and ropes are formed of a chemically inert, lightweight, high strength, plastic material, and wherein attachment loops may be readily defined on the anchor ropes and resilient means may be,

employed with the anchor ropes to permit the resilient longitudinal extension thereof without modification to the rope itself.

Another object of the invention is to provide swimming pool cover apparatus including a cover screen which is attractive in appearance, is of high strength, and can be installed in a taut horizontal position without additional supports and floats.

A further object of the invention is to provide a novel extensible, flexible, tension member which may be constructed from relatively nonextensible strand materials and is of high strength and lightweight.

These and other objects of the invention arising from the details and relationships of the components of an embodiment thereof will be apparent from the following description and accompanying drawings wherein:

FIG. 1 is a perspective view of a swimming pool, with a partial deck having cover apparatus in accord with the invention employed therewith,

FIG. 2 is a perspective view of a deck anchor plate,

FIG. 3 is a sectional, elevational, detail view of another embodiment of deck anchor taken along section llIIlI of FIG. 1,

KG. 4 is an elevational, partly sectional view of a ground anchor stake as taken along section IVIV of FIG, 1,

FIG. 5 is a perspective view of the anchor pin employed in accord with the invention,

FIG. 6 is an enlarged detail view of a binder tab loop sewed upon the cover binder,

FIG. 7 is a plan view of an anchor rope as employed with the invention,

FIG. 8 is a detail, enlarged view, partially sectioned, illustrating the formation of the loops in the anchor rope,

FIG. 9 is a sectional view of the elastomer element and rope taken along IX-IX of PEG. 7,

FIG. 10 is an elevational, sectional view of another embodiment of elastomer element having enlarged ends,

FIG. 11 is an elevational, detail view of a rope in which the element of FIG. 10 is positioned,

FIG. 12 is an elevational, detail view of the rope of FIG. 11 under tension, and

FIG. 13 is a sectional view of an elastomer element formed of foam material.

The relationship of the cover apparatus to a pool to be covered will be appreciated from FIG. 1 wherein a rectangular cover is illustrated as covering a rectangular pool opening therebelow. The cover proper consists of a cover screen it? of a semiclose weave. The weave of the screen is such as to permit water to pass therethrough such that rain or melted snow will not accumulate upon the cover. The weave should be close enough to prevent debris from passing therethrough, shade the pool against sunlight,

and act as a barrier against the air passing thereover to retain heat within the pool water.

Preferably, the screen cover is formed of molecular oriented monofilaments of polypropylene, a lightweight, high strength chemically inert, synthetic plastic which is lighter than water. The peripherial edge of the screen cover in is bound by a binder 12 preferably constructed of heavy polypropylene filaments, and the binder may be sewed to the screen cover by means of any high strength, synthetic thread which is also relatively chemically inert. Loops or tabs ltd are sewed to the binder 12 at the corners and at evenly spaced locations therealong for attachment to the anchor ropes. Such tabs are more desirable than grommets as they are capable of transmitting higher forces to the binder without damage thereto. For appearance purposes the filaments employed in the cover screen and binder preferably are of attractive permanent colors which are impregnated into the filaments during manufacture. I

The cover screen it is maintained in position by a plurality of anchor ropes 16 attached to the loop tabs 14 at one end and attached to anchor means at the other. Mews are provided wherein the anchor ropes are longitudinally, resiliently extendable whereby a tension may be maintained upon the cover screen. The anchor ropes employed in the practice of the invention are best shown in FIGS. 7 through 9 wherein the rope consists of a plurality of flexible loosely braided strands T08 of synthetic material, preferably oriented polypropylene, which are brm'ded in such a manner as to provide a tubular cross sectional rope configuration, see FIG. 8. As will be noted, each of the strands spirally extends the entire length of the rope. Thus, it will be appreciated that the rope has a central, axial, bore 20 defined therein and that the rope construction is such that the cross sections diametrical dimension of the rope will be afiected in 3J0- cordarrce with the tension forces transmitted thereby. The higher the tension force within the rope the greater the tendency will be to reduce the diametrical dimension of the rope, within limits, of course. Upon imposing an axial compressive force upon the rope, the rope diameter and bore thereof will become enlarged and the spacing between the interwoven strands will increase.

The strands .18 are formed of a plurality of monofil-aments of molecular oriented polypropylene, and as the filaments of polypropylene have a smooth slippery surface, the friction between the strands and filaments is very low and the anchor ropes radial dimension will readily respond to the forces within the rope. It will 3 be understood that the normal configuration of the rope will be such that a relatively small bore 28' will be defined Within the rope in that the resistance of bending of the strands during interweaving will tend to prevent a highly compressed configuration. However, upon tension forces being imposed on the rope, the bore thereof will become smaller than in the nontensio-ned form and any object located within the here will be compressed by the encompassing strands, as Wfll be described later.

The connection of the anchor ropes 16 to the tabs l t and the anchor means is through the form of loops defined at the ends of the formed ropes. The above described construction of the ropes permits a very effective and attractive loop 22 to be formed by merely inserting a terminal end 24 of the rope, as shown in FIG. 7, back intothe bore 20 of the rope portion adjacent the terminal end. Such a loop formation is possible due to the loose weave of the rope strands and the fact that the bore may be substantially enlarged. To form the loop the operator merely needs to impose a compressive axial force on that portion of the rope into which the termina. end of the rope is to be inserted to open up the weave of the rope, or a tool may be inserted into the bore to enlarge the dimension thereof. Thereupon the terminal end 24 is inserted between the strands into the bore of the rope, and axially fed therein toward the other end of the rope until the desired mount of rope terminal end is located Within the rope bore 20. It will be appreciated that before the terminal end 24 is inserted into the rope bore between the rope strands that the terminal end will be passed about a tab or anchor pin whereby the resulting loop will effect attachment of the tab or anchor pin to the rope. Upon forming the loop as described, no further means are necessary to insure the maintenance thereof. As tension forces are imposed upon the rope, the weave thereof will tend to grip and compress the rope portion encompassed Within the rope bore, and the higher the tension force within the rope the greater will be the tendency of the rope to grip and maintain the terminal end thereof in the bee. Thus, the terminal end not slip or pull from the rope bore, and the loop will be effectively maintained in the rope. The ends of the monofilaments defining a terminal end 24 are fused together by heat to prevent unraveling and produce a hard, slightly bulbous, rope end facilitating gripping by the encompassing rope strands.

As it is desirable that the rope be resilient in a longitudinal direction to facilitate assembly of the anchor rope to the anchors and to place the cover screen under tension to maintain the same taut, such a longitudinal resilient characteristic may be produced in the rope of the invention without modification of the rope material or the rope itself by inserting a radially, and preferably longitudinally extensible, resilient member into the bore of the rope which is of a diameter sufiicient to radially expand the rope here. In the preferred practice of the invention, the resilient member located within the rope bore consists of an elastomer element located between the ends of the rope. The element may be inserted in place by opening the strands of the rope and inserting the element into the bore 20 between the parted strands. In that the elastomer element Will expand the rope portion encompassing the element, the rope braid will be opened in the encompassing portion, and as tension forces are applied upon the rope the tendency of the rope to radially contract will be imposed upon the resilient element reducing the diameter thereof, thus permitting the rope to expand longitudinally and the resilient nature of the element will tend to expand the rope encompassing the element upon the release of the tension fences compressing the element. The fact that the element will also stretch in a longitudinal direction also significantly aids in the resilient effect produced by the elastomer element as will be apparent from the following detailed description.

Referring to FIGS. 7 and 9, an embodiment of the above inyentive concept is illustrated showing the elasto mer element in the form of an elastic tube 26 of uniform cylindrical diameter. The tube 26 may be formed of neoprene, synthetic or latex rubber, or similar material, and die regulation of the physical characteiistics of the tube such as OD, wall thickness, length, density, etc. will determine the degree and character of rope ex ension and contraction. v

The strands 18 encompassing the tube 26 will be open with respect to the weave of the remainder of the rope and will engage and grip the tube throughout its length due to the tube enlarging the diameter of the bore 243*. It will be appreciated that upon the insertion of the tube into the bore the length of the rope will shorten due to the increase in the diameter of the spirals defined by the strands in the tube-encompassing region. Upon tension forces being applied to the loops Z2, the braided strand weave will cause the tube as to be radially com pressed and longitudinally extended due to the tendency for the rope strands to orient themselves inthe direction of the tension forces and the effective length of the rope will resiliently increase. Upon removal of the tension forces the resultant radial expansion and longitudinal contraction of the tube will shorten the rope length. I

While an elastomer element capable of both radial contraction and longitudinal expansion is most desirable in the practice of the invention, the rope length can be made resilient by means of a spring within the rope bore capable of radial expansion and contraction only, as long as the strands will slide on the spring as they become more parallel to the rope axis under tetision or opened during radial expansion of the spring. 7

Another embodiment of an elastomer element is showri in FIGS. 10 through 12 wherein the element comprises a latex rubber tube 28 having plugs 3th inserted into the ends thereof to define enlarged portions 32 with respect to the central tube portion 34-. The formed tube 28 is inserted into the bore 20 of the rope resulting in a rope having an exterior appearance as shown in FIG. 11 in the normal state. Upon the rope 20 being placed under ten sionthe strand portions engaging portions 32 will firmly grip the tube 28 at these tube end regions such that initial elongation and resiliency of the rope will be determined by the longitudinal extension characteristics of the tube.- This is due to the fact that the strands are exerting little or no radial contraction on the tube due to the enlarging of the rope bore at the portions 32. As rope extension continues the strands 18 engaging tube port-ion 3 contract upon the tube radially compressing the same, FIG. 12, and the force necessary to increase rope length substantially increases. This embodiment produces a relatively high initial expansion with :a sharp increase in resistance to extension near the extension limits, thus providing a cushioning effect. It will be appreciated that the enlarged tube end portions 32 may be formed by means other than those disclosed, such as preforming the tube material or folding the tube ends back upon themselves. If desired, the elastomer may be in the form of a solid elastic member, rather than tubular.

Another embodiment of an elastomer element is shown in HG. 13 which comprises an elongated piece of resilient foam material 36 encased within the rope bore 20 for the expansion of the strands 18. This type of elastomer element is suitable Where extensive elongation is desired and the desired resiliency force is relatively small.

Anchor means must be employed with the anchor ropes 16 to permit the same to be placed under tension and maintain the cover screen taut and in position. One form of anchor device may be the anchor deck plate shown in FIG. 2 which consists of a disc-like body 38' having a groove 4n defined therein of a configuration similar to a rope loop 22. The portion 42 of the disc which is located within the groove is provided with a lip 44 extending over the groove to prevent the rope loop from slipping out of the groove. The plate 38 may be glued to the deck 45 of the pool by a high strength cement and as the plate is of a rounded configuration and closely conforms to the deck, its presence thereon does not become objectionable.

Another type of anchor which may be mounted in the pool deck is shown in FIG. 3 and consists of a cylindrical tubular member 46 having an upper surface 48 and a shoulder 50. An axial bore 52 is provided therethrough. The lower end of the cylindrical member is encompassed by a cap 54 afiixed thereto having a portion 56 in parallel spaced relation to the shoulder 50. The member 46 may be atiixed to the pool deck with the upper surface 48 thereof substantially flush with the deck by either maintaining the body member in position while the deck is being poured, if the deck is formed of cement or other similar moldable material, or a hole may be drilled in the deck and the member 46 inserted into the hole and cemented therein by suitable bonding means.

When using the anchors of FIG. 3 and FIG. 4, the anchor pin 58 best illustrated in FIG. 5, is employed and affixed to a loop in the anchor rope. The pin 58 includes a hole 60 through which the anchor rope is passed to attach the pin thereto, as shown in FIG. 7. The lower end of the pin is of a tapered configuration wherein a shoulder surface 62 is defined upon the upper end of a cylindrical knob 64 which is slightly smaller than the diameter of the anchor bore 52. The configuration of the pin 58 is such that the shoulder surface 62 may cooperate with the shoulder 50 of the member 46 upon the pin being tilted within the anchor bore, as shown in FIG. 3. Therefore, it will be appreciated that the anchor pin may be inserted into the anchor bore and the cooperation of the shoulder 62 with the shoulder 50 will prevent the anchor pin from being withdrawn from the anchor until the axis of the knob 62 is aligned with that of the anchor bore.

When the shape of the pool and deck is such that the anchor rope anchors cannot be attached to the pool deck or if no deck exists, the stake anchor of FIG. 4 may be employed which consists of a tubular stake 66 having a formed, sharpened lower end for facilitating driving the stake into the ground. The upper end of the stake is provided with a cylindrical plug 68 press fitted or otherwise afiixed thereto, having an axial bore 72 therein and a lower surface '70.

The bore 72 and lower surface 70 cooperate with the anchor pin 58 in the manner described in conjunction with the embodiment of FIG. 3 to permit the anchor pin to be attached to the ground anchor stake.

Due to the construction of the cover screen binder 12, and anchor ropes 16, of a material .such as polypropylene, the cover apparatus is of very lightweight and may be easily installed by a single operator. Furthermore, the lightweight and floating characteristic of the polypropylene eliminates the necessity of stringers or other screen supporting means in most applications, and the chemically inert characteristics of the material in sures a long life as it is not affected by weather or pool chemicals. The anchor components are preferably constructed of aluminum which also minimizes corrosion. While the pool cover is shown of rectangular configuration, it will be understood that the cover may be of any configuration desired to cover any shape of pool, and that the anchor tabs and anchor ropes will be located in those positions to effectively maintain the cover in position. Whether the deck anchors of FIG. 2 or FIG. 3 are employed is a matter of choice and as the length of the anchor ropes may be readily varied by varying the amount of rope terminal end inserted into the rope bore, a versatility of the apparatus is produced which makes the initial preparation an installation of the device a simple process capable of being performed by the pool owner.

A unique feature of the anchor rope construction lies in the fact that extreme tension forces imposed upon the rope will not damage the elastomer element or affect the resiliency of the rope produced by the element. As the rope strands extend the entire rope length, the strands themselves will always hear the eifect of high tension forces and the elastomer element will not be unduly longitudinally extended, and as the element is encased within the strands damage due to excessive compression is unlikely.

It will be understood that various modifications to the disclosed embodiments may be apparent to those skilled in the art without departing from the spirit and scope of the invention, and it is intended that the invention be defined only by the following claims.

I claim:

1. A cover for a swimming pool comprising a screen member composed of interwoven filaments, binding affixed to the periphery of said screen member, said binding comprising a closely woven fabric of filaments, fabric loops afiixed to said binding, anchor ropes aflixed to said fabric loops, said ropes being of a tubular cross sectional configuration having an axial bore and constructed of a plurality of loosely woven braided strands of filaments wherein the diametrical dimension of said rope may vary in accordance with the tension forces imposed on the rope, and a resilient member of greater normal diameter than the normal diameter of the rope bore located within the rope bore diametrically expanding said rope bore at the location of said resilient member and resiliently resisting radial contraction of the rope portion encompassing said resilient member, and thereby resiliently resisting elongation of said rope.

2. In a cover as in claim 1, wherein said ropes are constructed of polypropylene strands.

3. In a cover as in claim 1, wherein said screen member, binding, loops, and strands are formed of polypropylene filaments.

4. In a cover as in claim 1 wherein said resilient member comprises a tubular elastic tube.

5. Cover apparatus for swimming pools and the like comprising, in combination, a lightweight cover adapted to be horizontally stretched over the pool opening, longitudinally stretchable anchor ropes attached to the periphery of said cover, anchors affixed to the terrain surrounding the pool, said anchors including a vertically disposed tubular member having a top and bottom, a bore within said anchors, a downwardly facing shoulder defined on said anchors transversely disposed .to the axis of said bore and intersecting said bore, an anchor pin carried by each of said rope-s having an elongated shank and a knob receivable within and completely remo vable from said anchor bore, said pin shanks and knobs being of lesser transverse dimension than said bore, a shoulder defined on each anchor pin knob remote from and facing the associated rope adapted to radially align with and abuttingly engage .with said downwardly facing anchor shoulder upon tilting of said pins within said anchors preventing withdrawal of said pin shanks from said anchor bores.

6. A longitudinally extensible tension member comprising, in combination, a tubular rope defined by a plurality of flexible braided strands having ends, tension force transmitting members defined on said rope adjacent said ends, said strands defining a longitudinally extending bore having a normal diameter when said rope is untensioned, and being braided such that the diameter of said bore will decrease as tension forces are imposed on said rope and a radially contractible resilient member having a diameter at least as great as the normal diameter of said rope bore within said rope bore intermediate the ends thereof and enlarging a portion of said bore when said rope is tensioned biasing the strand portions defining said bore portion radially outwardly.

7. In a longitudinally extensible tension member as inclaim 6 wherein said radially contractible member comprises an elongated elastomer element capable of radial contraction and longitudinal extension.

8. A longitudinally extensible tension member comprising, in combination, a plurality of flexible strands braided to define a tubular rope having a longitudinally extending bore and terminating ends, an elastomer element of a diameter larger than the normal diameter of said bore within said bore intermediate said ends, said element being gripped by the strand portions defining the bore portion receiving said element and attachment means defined on said rope on opposite sides on said elastomer element, whereby upon tensioning of said rope said element resiliently resists contraction of the strand portions gripping said element and resiliently resists elongation of said rope.

9. In a longitudinally extensible tension member as in claim 8 wherein said elastorner element comprises an elongated cylindrical body member having end portions and a central portion, said end portions having a greater dia-metrical dimension than said central portion.

10. In a longitudinally extensible tension member as in claim 8 wherein said elastomer element comprises resilient foam material.

11. In a longitudinally extensible tension member as in claim 8 wherein said attachment means include at. least one loop defined adjacent a rope end, said loop being defined by bending a rope end and the adjacent.

References Cited in the file of this patent UNITED STATES PATENTS 1,441,476 Baker Jan. 9, 1923 2,211,478 Pierce Aug. 13, 1940 2,713,327 West July 27, 1959 2,870,454 Schippert et a1. Ian. 27, 1959 2,870,455 Reeves Jan. 27, 1959 2,958,872 Meyer Nov. 8, 1960 FORElGN PATENTS 1,091,005 Germany Oct. 13, 196i). 

1. A COVER FOR A SWIMMING POOL COMPRISING A SCREE MEMBER COMPOSED OF INTERWOVEN FILAMENTS, BINDING AFFIXED TO THE PERIPHERY OF SAID SCREEN MEMBER, SAID BINDING COMPRISING A CLOSELY WOVEN FABRIC OF FILAMENTS, FABRIC LOOPS AFFIXED TO SAID BINDING, ANCHOR ROPES AFFIXED TO SAID FABRIC LOOPS, SAID ROPES BEING OF A TUBULAR CROSS SECTIONAL CONFIGURATION HAVING AN AXIAL BORE AND CONSTRUCTED OF A PLURALITY OF LOOSELY WOVEN BRAIDED STRANDS OF FILAMENTS WHEREIN THE DIAMETRICAL DIMENSION OF SAID ROPE MAY VARY IN ACCORDANCE WITH THE TENSION FORCES IMPOSED ON THE ROPE, AND A RESILIENT MEMBER OF GREATER NORMAL DIAMETER THAN THE NORMAL DIAMETER OF THE ROPE BORE LOCATED WITHIN THE ROPE BORE DIAMETRICALLY EXPANDING SAID ROPE BORE AT THE LOCATION OF SAID RESILIENT MEMBER AND RESILIENTLY RESISTING RADIAL CONTRACTION OF THE ROPE PORTION ENCOMPASSING SAID RESILIENT MEMBER, AND THEREBY RESILIENTLY RESISTING ELONGATION OF SAID ROPE. 